Add a builder for DefaultLink to hide multiplying constructors

Change-Id: Iaf073d07989c398a8f44541ffdb8dd93e5715162
diff --git a/core/api/src/test/java/org/onosproject/net/intent/constraint/ObstacleConstraintTest.java b/core/api/src/test/java/org/onosproject/net/intent/constraint/ObstacleConstraintTest.java
index f02787f..99cd338 100644
--- a/core/api/src/test/java/org/onosproject/net/intent/constraint/ObstacleConstraintTest.java
+++ b/core/api/src/test/java/org/onosproject/net/intent/constraint/ObstacleConstraintTest.java
@@ -62,8 +62,18 @@
     public void setUp() {
         linkResourceService = createMock(LinkResourceService.class);
 
-        link1 = new DefaultLink(PROVIDER_ID, cp(DID1, PN1), cp(DID2, PN2), DIRECT);
-        link2 = new DefaultLink(PROVIDER_ID, cp(DID2, PN3), cp(DID3, PN4), DIRECT);
+        link1 = DefaultLink.builder()
+                .providerId(PROVIDER_ID)
+                .src(cp(DID1, PN1))
+                .dst(cp(DID2, PN2))
+                .type(DIRECT)
+                .build();
+        link2 = DefaultLink.builder()
+                .providerId(PROVIDER_ID)
+                .src(cp(DID2, PN3))
+                .dst(cp(DID3, PN4))
+                .type(DIRECT)
+                .build();
         path = new DefaultPath(PROVIDER_ID, Arrays.asList(link1, link2), 10);
     }